Our Porsche guy Lee Rice replaced the bushings in the Black Plague's clutch pedal, though he spent a couple hours upside down in the footwell and got sunburn in a particularly unpleasant area to do it. It was a lot of trouble for $14 worth of plastic parts.
Afterwards Rice sent us a little note about the whole issue. It's interesting in its own right, but also it's a lesson that there's a lot more that goes into the way cars are built and subsequently evolve than we realize -- something that's especially true about the 911, which remained almost unchanged between 1964 and 1989. It's always amazing to discover what you think you know but don't. His report follows:
Anyway, having repaired your Carrera pedal bushings and reviewing my records as well as two articles I wrote on this very subject for my Orange County chapter of the PCA, I do know that the "creak-groan" sound that you reported in the clutch pedal action was mostly caused by a nylon bushing rubbing against the outer nylon spacer. The bushings were all a bit worn, but the locking pin was really scored. It comes from all that dirt and flaked water-damaged rust that’s been floating around under the floor board in the pedal area after 30 years.
I replaced your bushings with original (though later improved material) plastic bushings, as the bronze bushings actually wear faster, then click and clack in the pedal box frame and actually make a loose feel in the pedal action. I wore out two sets of bronze bushings on my 911 discovering this, so now I use plastic for my car and most customer 911s. I don't agree with everything that PCA techical guru Bruce Anderson says about maintaining 911s, but on the issue of the pedal bushings we agree.
The pedal box — the stamped-steel frame that contains the clutch pedal, brake pedal and throttle bell-crank — is actually the same size as it was in 1964 when the 911 was introduced. Those early 911s had a little 2.0 engine with a 215mm clutch, so you could push down the clutch pedal with your index finger. The side loads on the clutch pedal were minimal at most. Over the years engine power went up dramatically and Porsche adapted the car to stronger clutches. (The racing clutches for the 3.0 RSR were extremely strong!) These stronger clutches wrecked havoc with bushings, shafts, cables, and pivot arms. Even the mountings on the bell housing sometimes tore out!
To make way for the bracing required for the brake pedal when vacuum-assisted brakes were introduced (and then later the clutch-pedal starter interlock), the pedal box got longer shafts to move the clutch cable over in the center of the tunnel down the middle of the platform. So when you actuate the clutch pedal in your Carrera 3.2, the clutch cross-shaft moves slightly downward on the pedal side and upward on the cable side. And the longer clutch cross-shaft introduced for the Carrera 3.2 makes the side-to-side play in the pedal and the friction in the pedal movement even more noticeable.
Even if you install a brand new pedal box, you’ll always notice the same thing. There’s always some looseness in the action and when you uncover the linkage you can observe the pedal arm, cross-shaft and cable end move around a bit. It looks so imprecise and kind of un-Porsche like, but it does work pretty well.
Since the original pedal box is exactly the same size as it was in 1964, the stamped steel frame is under-strength to say the least, so you just have to live with the compromise. I could tell you a lot more about just this issue, but this has probably already put you to sleep!
Lee Rice, Rice's Performance Porsches, Garden Grove, CA
Michael Jordan, Executive Editor, Edmunds.com @ 117,538 miles
brian_k says:
08:33 AM, 08/31/11
Not that it is happening tomorrow anyway, but I won't buy my 993 Turbo until I find a guy like this in my area so that I know what I am buying and have someone this knowledgeable and (assuming) trustworthy to service my car.
cjasis says:
09:25 AM, 08/31/11
Another great example of why you may have foolishly bought the wrong 911 but are smart enough to take it to the right mechanic.
I've said it before and I'll say it again, Mr. Rice knows his stuff and he's honest, passionate about the cars and what he does and perahps just as important, he's a good guy.
banhugh says:
09:32 AM, 08/31/11
How much has this car cost you as of today? Thanks!
blueprint1 says:
10:20 AM, 08/31/11
Wow...sure beats the "can't reproduce" reports of dealerships!
banhugh says:
11:02 AM, 08/31/11
@blueprint1:
"can't reproduce" reports of dealerships are for fixing stuff under warranty for free.
I wonder how much this personalized response cost. And please IL, can you answer the question of how much you have spend on this car? Thanks!
felonious says:
11:06 AM, 08/31/11
My goodness! That's one heck of a mechanic! He's living proof, there's no school like the old school.
doss1 says:
01:58 PM, 08/31/11
A cost total was posted previously. Check through the blogs.
desmolicious says:
02:22 PM, 08/31/11
My Ducati mechanica - John Waters at Motoservizio in Signal Hill, CA - explains things the same way.
It's really nice to get the straight dope, and funny how this does not happen at official dealerships.
msh1 says:
02:58 PM, 08/31/11
Thank you, Inside Line. Posts about this car and Project Miata make this site worth reading. Interesting, educational, and unique. Good stuff, and orders of magnitude better than we used to get in the weekly Johnson-size contests following posts about Regals and Saturns.
Bravo. Keep it up -- it's great to read these posts and actually LEARN something.
banhugh says:
03:05 PM, 08/31/11
@doss1: Does it include work in this post? Which post was it? Thanks a priori for your informative answer
stovt001 says:
07:21 AM, 09/ 1/11
Wow, this guy is awesome.